Why tap the portafilter? - Page 2

[timo888]

Have you tried the zero tamp approach with anything besides a lever?

I don't own any other machines, but there's a shop on my way to work that has a Nuova Simonelli two-group. The shop's grind is quite fine and fluffy and doesn't need anything more than a very light leveling tamp. On a few occasions, I've asked the barista there not to tamp. One of them really puts some shoulder muscle into his tamps, and spends very little effort on distribution. He just presses the tamper down on the heaped mound. His untamped shots are tasty.

There used to be a woman barista there who would distribute with her pinky very carefully and thoroughly and then simply place the tamper in the basket and give it a couple of spins; her shots were good.

But the espresso made with the muscle-tamp approach channel badly. I would always ask him for an untamped shot, if it weren't for the fact that he is such a great believer in the power of the tamp and regards me as anathema for asking him to forego the main hierophantic element of his ritual bean sacrifice.

I've switched to mochas. He is not one to skimp on the whipped cream and chocolate syrup.

Regards
Timo

[wildlyesoteric (original poster)]

This is how I do it: grind> dose> Stockfleth-like thing> then tap> 22kg tamp (45lb?)> lock it in gently > great shot, no channeling.

I think the tap is needed to avoid air being trapped in the puck, and it makes it more solid. You can do the same with almost everything: try putting things like sugar in a container and fill it to the brim, after tapping there is still room for more. Heck: I even do it when I put coffee beans in the airtight container. I think the effect of tapping here is bigger than when I would try to compress the beans in the container. Isn't that why they use these big vibrators when they pour out concrete floors?

So I figure this will be the same with coffee ground (?)

Okay, not that tap. I'm talking about the intermediary tap between a soft and hard tamp where you tap the PF with the tamper as is common practice. FWIW I find myself giving the PF a rap (not a tap, now!) on the counter to settle the grounds, this yields better results for me (I left it out in the above sequence). I can't possibly imagine air being anywhere in the puck after a 45lb tamp -- I think it's all about distribution, let's call it 3-D distribution.


edit/condense:
When I see a 1lb tamp at WBC I'll take a harder look at it, until then I'll leave it to the Italians.

edit:
After reading about the no-tamp requests. I have a two-group Nuova Simonelli at work. For thoroughness I'll try out the tamper-weight tamp a couple times. I expect that the grind will need to change, as was the case the last time I tried it.

[HB]

I don't own any other machines, but there's a shop on my way to work that has a Nuova Simonelli two-group. The shop's grind is quite fine and fluffy and doesn't need anything more than a very light leveling tamp.

Indeed, Counter Culture had the Aurelia in for evaluation and it was a forgiving group (more info). They elaborate on their "soft infusion" design on their website:

All our units facilitate an industry-leading preinfusion chamber above the grouphead. The Aurelia not only uses our patented, single preinfusion technology, but also provides a second, inline "pressure dropping" mechanism located before the heat exchanger. These "double" features allow the 9 bar needed to produce an espresso to drop to 2 bar, presoaking the grounds and then evenly builds pressure back to the needed 9 bar. This process allows for more crema, more aromas to be extracted while also lowering employee's possible tamping/grinding errors.

Evidently your observation about 2 bar preinfusion holds for levers and the Aurelia.

[timo888]

When I see a 1lb tamp at WBC I'll take a harder look at it, until then I'll leave it to the Italians.

Si, lasciamo a quelli dannati barbari faccialo

edit:
After reading about the no-tamp requests. I have a two-group Nuova Simonelli at work. For thoroughness I'll try out the tamper-weight tamp a couple times. I expect that the grind will need to change, as was the case the last time I tried it.

Bravo

Timo

[wildlyesoteric (original poster)]

Evidently your observation about 2 bar preinfusion holds for levers and the Aurelia.

That's funny about the Aurelia being a forgiving machine. I had originally written in the last post that the Program VIP I work on is pretty unforgiving. It seems that there's a solid ramp-up to full pressure. I'll check the specs and see if there's info on preinfusion.

[Kaffee Bitte]

Tapping the pf with the tamper or anything else after tamping is just going to cause problems.

As to the light tamp on pump machines. I have worked with various commercial machines originally using a fairly standard to hard tamp. After a while I started trying to lessen my tamp because I was worried about joint injury later in life. I have tried the no tamp timo is speaking of on an Astoria, a La San Marco, and an LM Linea. I never personally was satisfied by the look or the flavor of the no tamp shots. What I finally settled on though would still be considered a light tamp. Finer grind is required without doubt. But the light tamp I use at work now is approximately 10 lbs pressure. Any less and the results are not up to par.

Recently on my lever at home I have been varying the amount of tamp I use. I have been moving away from the extreme light tamp in order to increase my dose a little. I have even tried the gorrila tamp a few times, though I was less than impressed with what came of it. As of now I am settling into ~10-15 lb tamp with a dose between 13-14 grams on my machine. This is more than I can normally fit in the basket with the light tamp.

[Spironski]

I can't possibly imagine air being anywhere in the puck after a 45lb tamp -- I think it's all about distribution, let's call it 3-D distribution

Oh yes I can. As I discribed with filling my coffee-container; when I fill it with beans to the brim, I could push down hard on the beans, but almost nothing would happen. Only when I "tap' the container, there seems to be space between al those beans and I can pour in some more. There is air between all those beans!

It seems that when you tamp, only the upper half will be compressed. It leaves you with an even compacted surface. Underneath that, grounds will stay a bit "loose'.
When you tap your PF on the counter however, you will settle all the grounds, and make your puck more solid as a whole. I guess 22kg or 15 kg, or even 10 kg after the tapping wouldn't make that big a difference (that is more about the 25 sec. extraction time). It is all about a solid puck without fractures or soft spots (so care-full distribution and tapping).

[Spironski]

When I see a 1lb tamp at WBC I'll take a harder look at it, until then I'll leave it to the Italians.

I have been a couple of times in Italy, and I have never have been served a bad espresso. One was okay, most very good and often they've been superb.

So what is it? is it knowledge? is it passion? They are doing something right down there!

[cannonfodder]

I use to tap for many of the same reasons stated above. It could also have been a case of monkey see monkey do, others did it so it must be good, the mob mentality. After a lot of reflection, I gave up on the mid tamp tap, I even gave up on the mid tamp around a year ago. I do give the portafilter three small thumps on my tamping stand to settle the grounds in the basket, then one tamp, brush off the stray grounds from the basket top and locking lugs and pull my shot.

As far as I can tell, the portafilter tapping serves no useful purpose; in fact it may do more harm than good. The entire reason you tamp is to create an evenly dense puck so the pressurized water flows evenly through the coffee cake. Water will seek the path of least resistance so any change in density will result in more/less flow through the puck. Tapping on the portafilter could jostle the coffee cake and create a fissure or break the side cohesion with the basket. Both of those will lead to channeling. I have noticed no ill effects from stopping the tamp, tap, tamp ritual and I may have a few less sink shots because of it. The stray grounds on the sides of the basket do no harm.

[wildlyesoteric (original poster)]

Tried the 1lb flattening tamp today, ended up going of full number on the MDX finer (significant). In the words of Mia from Pulp Fiction, "I say gatDAMN". Great flavourful shot. Different, but very nice; a little more sweetness I found than with a conventional (NA Terms) tamp, at least with the blend used.

That being said, this thread isn't about tamping or not, so that's all out of context.

Anyway, I think the tap should be phased out. I doubt it's doing any good to anybody out there.


Full extractions FTW!